devpanel: simplify file opening code
devpanel: simplify file opening code

tyanas/basisjs,istrel/basisjs,basisjs/basisjs,smelukov/basisjs,fateevv/basisjs,fateevv/basisjs,tyanas/basisjs,basisjs/basisjs,fateevv/basisjs,tyanas/basisjs,basisjs/basisjs,istrel/basisjs,smelukov/basisjs,smelukov/basisjs,istrel/basisjs